Many species exhibit prosocial behavior, in which one individual’s actions benefit another individual, often without an immediate benefit to itself. The neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. Here, we experimentally tested prosociality in pinyon jays (Gymnorhinus cyanocephalus), a highly social corvid species that spontaneously shares food with others. First, we measured prosocial preferences in a prosocial choice task with two different payoff distributions: Prosocial trials delivered food to both the subject and either an empty cage or a partner bird, whereas Altruism trials delivered food only to an empty cage or a partner bird (none to subject). In a second experiment, we examined whether administering mesotocin influenced prosocial preferences. Compared to choices in a control condition, we show that subjects voluntarily delivered food rewards to partners, but only when also receiving food for themselves (Prosocial trials), and administration of high levels of mesotocin increased these behaviors. Thus, in birds, mesotocin seems to play a similar functional role in facilitating prosocial behaviors as oxytocin does in mammals, suggesting an evolutionarily conserved hormonal mechanism for prosociality.
All data from Experiment 1 (no hormonal manipulation) and Experiment 2 (mesotocin manipulation)
These data come from a prosocial choice task conducted on captive pinyon jays. Experiment 1 measured baseline preferences (i.e. without hormonal manipulation), and Experiment 2 involved administration of a high or low dose of mesotocin (the avian homolog of oxytocin) or a saline control. Description of the relevant columns for "all_data.csv":
A: dataset - either 1 (for Experiment 1, no hormones) or 2 (for Experiment 2, with hormonal manipulation)
B: donor - a unique numeric identifier for each subject in the study
C: date - date that session in corresponding row was conducted
D: session - sequential numbering for each subject's session
E: trial - specific trial number within a session
F: partner - location of partner (either N- no partner, L-left sidecage, or R-right sidecage)
G: recipient - if present, a unique numeric identifier for each recipient in the study
H: payoff_condition - trial type; either Pre-Test (attention trials), Side bias (bias trials), or Prosocial/Altruistic
I: partner_present - either 'Partner absent' or 'Partner present'
J: hormone - hormone condition: NA for Experiment 1; A, B, C, or SAL for Experiment 2 (experimenters were blind to condition)
K: right.left - subject's choice on that trial, either right or left wire
L: response - FOR PRE-TEST (i.e. attention trials): 1 if subject correctly chose side with food, 0 if incorrect
L: response - FOR SIDE BIAS (i.e. bias trials): 1 if subject chose LEFT, 0 if RIGHT
L: response - FOR PROSOCIAL/ALTRUISTIC: IF partner absent, 1 if subject chose LEFT, 0 if RIGHT
L: response - FOR PROSOCIAL/ALTRUISTIC: IF partner present, 1 if subject chose same side as partner, 0 if not.
all_data.csv
Supp. Materials for Duque et al 2018 Jay Prosociality
This document contains Supplementary Methods (Subject information, detailed procedure for habituation/training and experimental phases, and additional analyses (weighted prosocial/altruistic tendency) and figures.
Duque et al Supplementary Materials.pdf
Duque_et_al_2018_rcode
This Rcode is for Duque et al. 2018 Mesotocin influences pinyon jay prosociality. It is annotated for replication of all results, figures, and analyses. Absolute tendency appears in main text; Weighted tendency in supplementary.